Intratumoral Low-Volume Jet-Injection for Efficient Nonviral Gene Transfer

Abstract

Jet-injection has become an applicable technology among other established nonviral delivery systems, such as particle bombardment or in vivo electroporation. The low-volume jet injector employed in this study uses compressed air to inject solutions of 1.5-10 microL containing naked DNA into the desired tissue. The novel design of this prototype makes multiple jet-injections possible. Therefore, repeated jet-injections into one target tissue can be performed easily. This jet-injector hand-held system was used for the direct in vivo gene transfer of plasmid DNA into tumors to achieve efficient expression of reporter genes (beta-galactosidase, green fluorescent protein [GFP]) and of therapeutic genes (TNF-alpha) in different tumor models. The study presented here revealed the key parameters of efficient in vivo jet-injection (jet-injection volume, pressure, jet penetration, DNA stability) to define the optimal conditions for a jet-injection-aided nonviral gene therapy.

Uptake, Biodistribution, and Time Course of Naked Plasmid DNA Trafficking After Intratumoral In Vivo Jet Injection

“…Jet injection-mediated intratumoral gene transfer of reporter gene-expressing plasmids or therapeutic gene-expressing constructs led to the expression of these genes in various tumor models, using only small amounts of naked DNA (Walther et al, 2001(Walther et al, , 2002. Similar results have been reported when muscle tissue was targeted for jet injection gene transfer (Furth et al, 1992(Furth et al, , 1995Cartier et al, 2000).…”

“…Because nothing is known about the in vivo fate of focally jet-injected naked DNA in tumors or about its systemic biodistribution and clearance, our study has focused on this issue, using quantitative real-time PCR. For this we applied 50 g of pCMV␤ DNA by jet injection, knowing that such dosing had been shown to be effective for transgene expression in tumor tissue in vivo (Walther et al, 2001(Walther et al, , 2002.…”

“…When tumors reached a size of approximately 6 ϫ 6 mm the tumor-bearing animals were anesthetized and received five intratumoral jet injections of pCMV␤ plasmid DNA through the skin, using a Swiss Injector prototype (Electro Medical Systems, Nyon, Switzerland) at a pressure of 3.0 bar, a condition optimized in previous studies for in vivo gene transfer (Walther et al, 2002). These jet injections were applied at five different sites in the tumor (see Fig.…”

DNA electrotransfer: its principles and an updated review of its therapeutic applications

“…7,8 For the 'jet injection' or 'needle-free' injection, the DNA is pushed at high pressure and high speed through a tiny orifice at the head of the injector, creating an ultrafine stream of high-pressure fluid that penetrates the skin. 9,10 (iv) The proof of the concept of sonoporation (use of focused ultrasounds to permeate the cells) has just been developed and still requires further elaboration. 11 (v) DNA electrotransfer has been used with success since 1998 and is becoming a real alternative to the viral methods for in vivo gene transfer.…”

Transferência gênica in vivo por meio de eletroporação em músculo sóleo de ratos wistar.

“…Outro vetor físico, a biobalística ou "gene gun", utiliza micro partículas de ouro onde são encapsulados os plasmídeos, para que posteriormente sejam projetados, em alta pressão, em direção a um anteparo (geralmente a pele), conseguindo uma transfecção precisa, mas muito localizada e em quantidade diminuída (WALTHER et al, 2002).…”